▎ 摘　　要

NOVELTY - Preparing a potassium ion selective film involves adding graphene oxide powder and dimethyldimethoxysilane liquid into deionized water, heating, stirring until completely dispersed, cooling the solution to room temperature to form a colloidal solution, adding a certain amount of colloidal solution dropwise on the porous substrate polyethylene terephthalate film, and naturally air-drying to obtain the functionalized graphene oxide film. The dried functionalized graphene oxide film is placed into 0.1-0.5 M potassium chloride (KCl) solution, taken out after adsorption at room temperature for 10-24 hours, and the excess ionic solution on the surface of the functionalized graphene oxide film is rinsed off with ionized water, dried with nitrogen to prepare potassium ion functionalized graphene oxide film. USE - Method for preparing a potassium ion selective film. ADVANTAGE - The method utilizes the graphene oxide film as the ion transmission channel and the dimethyldimethoxysilane functional molecule as the potassium ion adsorption site, and helps in realizing the selective passage of potassium ion. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a potassium ion selective film.